Does weed control by precision spray technology favour the emergence of resistance?

Weed control by precision farming is recommended both by economic and ecological reasons. It is still unclear
whether precision weed control favours the emergence of herbicide resistant biotypes. To investigate this, the
cellular automaton model of Sandt et al. (2008) for the simulation of precision weed control was extended to
resistant biotypes and their genetic interactions. The model is capable of simulating the emergence of
resistant biotypes in dependence of weed control thresholds, application rates and initial distribution of
biotypes. Examples are shown for the case of polygenic inheritance of resistance involving three loci and thus
27 biotypes. Preliminary simulation results hint that precision farming can delay the emergence of resistance at
high weed control thresholds.